Cylinder lock



Se t. 2, 1969 I p. M. HAWKINS 3,464,243

CYLINDER LOCK Filed June 28, 1967 2 Sheets-Sheet 1 M. HAWKINS CYLINDERLOCK 2 Sheets-Sheet 2 Sept. 2, 1969 Filed June 28. 1967 United StatesPatent U.S. Cl. 70-364 19 Claims ABSTRACT OF I THE DISCLOSURE Keyoperable tamper-proof cylinder lock with means affording limitedrotation of bolt controlling plug insufficient to retract bolt "uponattempted unauthorized manipulation; and cooperating means actuatingalarm upon such limited rotation.

This invention relates to a lock mechanism, and more Patented Sept; 2,1969 be provided to resist return of the second plug to its normalposition after a preselected amount of rotation. In this way, that plugmay be utilized to operate an alarm upon attempted unauthorizedmanipulation of the lock, about which more will later be said.

A key slot is provided in the first plug so that the vari.

' ous standard and non-standard tumbler and driver asparticularly, to atamper-proof pin tumbler cylinder lock '1 mechanism with whichcooperating means for actuating an alarm upon attempted unauthorizedmanipulation of the mechanism may be associated.

Various types of alarm actuating mechanisms are known wherebyunauthorized entry into a locked prem- I has taken place. As thesecurity technology has advanced,

the development of means to nullify the improvements has also advanced.Thus, there has been a long standing need for a tamper-proof lockmechanism which, while operable to permit authorized entry, resistsunauthorized entry and may be combined with means to actuate an alarmupon attempted unauthorized entry. The invention disclosed in mycopending application Ser. No. 623,333, filed Mar. 15, 1967 and entitledLock Mechanism and Alarm provides a very satisfactory solution to thisproblem; and while the present invention attacks the same problem, itprovides a solution based upon an entirely novel inventive concept.

Accordingly, an important feature of the present invention resides inapparatus of the class describedcomprising; a cylinder, a plug rotatablymounted in the cylinder, standard pin tumbler and driver means normallysecuring the plug against rotation relatively to the cylinder, at keyslot in the plug for reception of means adjusting the pin tumbler anddriver means to permit such relative rotation, and means allowinglimited rotation only of the plug relatively to the cylinder uponunauthorized manipulation of the standard pin tumbler and driver means.

To this end, I prefer to employ a second plug also mounted for rotationin the cylinder and adjacent to the first plug, the plugs havingnormally opposed bores in which are positioned what I shall refer to asnon-standard tumbler and driver assembly means. These assembly meansinclude a pin tumbler, a driver and spring means, the latter urging thetumbler and driver into position to avoid establishment of anuninterrupted shear line between the plugs. The pin and driver assemblymeans may be so constructed and arranged relatively to the bores thatthe second plug is free to rotate a limited distance in either annulardirection upon rotation of the first plug when the assembly means are innormal position, and, in

fact, it is these non-standard assembly means that transmit the motionfrom the first to the second plug. Detent means such as a socket andspring loaded ball may act between the cylinder and plug tending toresist such annular movement. Moreover, similar detent means '-maysembly means may be set to establish an uninterrupted shear line betweenthe plugs, and between the respective tumblers and drivers in the usualway, so that the key slotted'plug is free to rotate independently of theother plug by the use of an authorized key. The key slotted plug maythus be arranged to operate a door bolt for instance.

According to one embodiment of the invention, the plugs are formed tointerfere with one another whenthe extent of limited rotation isreached. Thus for example, one of the plugs may be formed witharecessand the other with a projection extending into the recess, the recessand projection being constructed and arranged to interfere at apreselected annular position of rotation thus to effect a positive limitof such rotation. In such cases, it is my preference that the partscomprising the tumbler and driver assemblies be of a size that thetumbler and driver, when bottomed under the influence of theirrespective spring, are both contained within their respective bore inone of the plugs and do not intersect the shear line between the plugs.The spring itself, in such case, does intersect the shear line andaffords a toggle action when the plugs are rotated to the position oflimited rotation.

0n the other hand, the tumblers and drivers may be so dimensioned that,when bottomed, the drivers extend through the shear line. In this case,I prefer to form the bores of at least one of the plugs of a diameterslightly larger than that of the drivers to afford some degree of playtherebetween so as to allow limited rotation of the plugs when thedrivers intersect the shear line.

It will be appreciated by those persons skilled in the art that theforegoing arrangements permit authorized use of the lock mechanism by akey which positions the tumblers and drivers to afford an uninterruptedshear line between the plugs, such shear line also passing between therespective tumblers and drivers so that the key slotted plug may berotated independently of the other plug to operate a door boltretracting shaft, for example.

In addition tothe foregoing structure, as mentioned, I provide at leastone pin tumbler and driver assembly of the standard type, i.e., a pin, adriver and a spring dis- ..posed in cooperating bore means in the keyslotted plug and in the cylinder. These bore means are dimensioned toafford the usual clearance to the pin and driver to obviate play in thekey slotted plug. This standard assembly,

'or assemblies if more than one is used, is preferably in line with thetumbler and driver assembly means already described and is between themand the key slot opening and is operated by the same key which operatesthem.

However, ifan attempt is made to pick the lock, it would be necessary topick the standard assembly or assemblies first since the play in thenonstandard assembly means makes it exceedingly unlikely that the pickedcondition of the respective nonstandard assembly means could bemaintained while others were being manipulated; in-

stead any that had been picked would fall back into normal positionsince the standard assemblies would prevent suflicient rotation of thekey slotted plug to afford a ledge at the top of that plug upon which tomaintain a picked driver while others were being manipulated.

On the other hand, if the standard assemblies are picked successfully,then any torque applied to the key slotted plug sutlicient to causerotation thereof, will in turn cause counter rotation of the other pluguntil the limit of 'such rotation is reached, and as this occurs afterrotation of the order of 15 or less;thekey'lottedplug will be lockedagainst further rotation before it has rotated sufiiciently to effectretraction of a door bolt. In this connection, it will be' understoodthat in the embodiment employing, in the tumbler and driver assemblymeans; springs thatnormally intersect the shear line, a toggle action isgiven to rotation of the'plugs so that only a very slight the designingof other structures for carrying out the several purposes of'theinvention.

.A' specific embodiment of the inventionhas been chosen for purposes ofillustration and description, and is shown in thc accompanying drawings,forming apart of the specification where:

FIG. 1 is a vertical cross-sectional view of a cylinder lock inaccordance with the present invention and illustrating a bolt operatingshaft controlled by the first plug, a switch and switch operatingmechanism controlled by the second plug and a key setting the varioustumbler and driver assemblies to normal entry position;

FIG. 2 is an elevational view taken along the lines 2--2 of FIG. 1;

FIG. 3 is a partial elevational view illustrating a switch and switchoperating elements;

FIG. 4 is a cross-sectional view taken along the lines 4-4 of FIG. 1;

FIG. 5 is a view similar to FIG. 4, but illustrating the parts inposition of limited rotation;

FIG. 6 is a view similar to FIG. 2, but illustrating the parts inposition of limited rotation; and

FIG. 7 is a view similar to FIG. 6, but illustrating another embodimentof the invention.

Referring now to the drawings in detail, andvmore specifically to FIG.1, there isshown a cylinder 10 having a pair of plugs 11 and 12 mountedfor rotation therein. The plugs are shown as being equal in diameter andmounted adjacent one another with their longitudinal axes parallel; butthe uppermost plug 11 is shorter in length than is the plug 12 and doesnot extend to the front face of the cylinder 10. I A standard pintumbler and driver assembly 14 is shown positioned in cooperating bores15 and 15ain the cylinder 10 and plug 12, respectively. This assemblycomand that which intersects the shear line, is closely coiled tensionsprifigrora' purpose later to be'described."

Returning to FIG. 1, the plug 12 is a key slotted as at for reception ofa key 23 which adjusts the standard and nonstandard assemblies so,thatthe shear line between the plugs also passcsj betweenthe drivers andtumblers of all the assemblies .whereupon the plug 12is freetor'otateind ependentlyof the .plug "11. A shaft 26 rotates with theplug 12 to operate a conventional door bolt or the like? As stated, inthis embodiment" of the invention, one lng'i's formed with a recess andthe other with a projection extending into the recess,.the recess andprojection being constructed and arranged to interfere at a preselectedannular'positionof f otation thus positively to limit the extent .ofsuchrotation. Tothis end,-I extend the plugs somewhat beyondtheinnerendof the cylinder. 10 .(FIG. .1) andQasshown in FIG. 2, form an arcuaterecess-27in thC1OWf marginal region of the upper plug 11. The lower plug12 is milled10ut as at 28 and has an upstanding projection 29 in itscorresponding region so arranged that it fits"intothe' medianarea of therecess 27 when the plugs are in normal position. Additionally,

" thearcuate recess 27 is dimensionedso as not to interrare withrotationof the plug 12 when an uninterrupted shear line isetfected between theplugs, so that the plug 12 can'rotate independently of the plug 11.However, as

, shown in FIG. 6, if the shear line is interrupted as by one of thespring means 24,- then a rotating force applied to the plug 12 will betransferred to the plug 11 through the spring and the latter plug willrotate in a direction counter to ,the direction of rotation of the plug12; and

, as mentioned before, the closely coiled portion of the spring meansinterrupts the shear line thus giving a snap or toggle effect to therotation. Such rotation is limited by interference between the outersurface of the plug 11 and the side of the milled portion of plug 12, asshown in FIG. 6 at, 30. When this degree of rotation is reached,

" ent lock mechanism, the upper plug 11 is shown in FIGS.

1 and 3 equipped with a shaft 31 to which is. attached for rotationtherewith a cam 32 having a recess 34 in which a follower 35 sits whenthevplug 11 is in normal position. When the plug 11 is .rotated ineither direction, and before it reaches its limit of rotation, the shaftprises a pin tumbler 16, a driver 17, both of drill-proof hardenedsteel, and a spring 19 normally urging, the driverand tumbler intoposition 'to lock the plu 12 against rotation. This assembly isconventional and, although only one is shown, it will be 'understoodthatseveral may be used. i V p A series of nonstandard pin tumbler anddriver assemblies such as that designated by the reference numeral 20are shown behind and in line with the standard assembly 14, thesenonstandard assemblies comprising tumblers 21, drivers 22 havinginverted mushroom-like configurations, and spring means 24 urging thetumblers and drivers to, bottom in the lowermost, of corresponding bores11a and 12a of the plugs 11 and 12, respectively.

Referring momentarily to FIGS. 4 and 5, itwillbe seen that the variousparts of the nonstandard assemblies are so dimensioned that in normalposition, the tumblers 21 and drivers 22 are contained within the bore12a of plug 12 while the spring means 24 occupies the bore 11a of plug11 and intersects the shear line between the plugs. It will be notedthat the upper part of the spring means 24 is a compressionspring whilethe lowermost portion,

31 and cam 32 also rotate sufliciently to lift the follower 35 out ofthe recess. This movement of the follower lifts 'a switch actuating arm36, and operates a switch 37 to energize an alarm circuit. The plug 11is also bored as at 39 (FIGS. 1, 2 and 6) for receipt of a ball 40 andspring 41, the latter normally urging the ball against the surface ofthe cylinder 10. The inner surface of the cylinder however has a pair ofrecesses 42, one on each side of the vertical center line through theplug 11 and located toseat the ball 40, upon completion of the limitedrotation alreadyfdiscussed, to act as a detent restraining return of theplug 11 to its normal position. r In the embodiment of the inventionillustrated i FIG. 7, bores 11b in plug ,11 are of oversize diameterrelatively tospring's 44 and drivers 45, thelatter being of a lengthnormally .to extend across the shear line between the plugs. 'In'this,way, a limited degree of rotation of the plugs is permitted uponattempted rotation of the ,plug 12 while the shear line is interruptedby at least one driver. Such rotation is limited due to eventualinterference by the driver with the sides of the corresponding bores inthe plugs 11 and 12 and, if desired, the lower portion of the bores 11bmay be formed with annular ribs 46 for accurate control. I a

As shown in FIGS. 2 and 6, further detent means may be provided normallyto maintain the plug 11 in neutral position. Thus, a conical recess 47is formed in the side of the plug 11 and a ball and spring assembly 49are positioned in a bore 50 in the cylinder 10, the spring urging theball to seat in the recess 47 under a light force.

As shown in FIG. 1, a cup-shaped cap 51 is press fit or otherwisesecured over the front portion of the cylinder and is formed ofdrill-proof metal to prevent drilling through the cylinder for insertionof a shim to support the respective assemblies in picked condition asothers are manipulated; and this cap covers the shear line at the frontof the cylinder.

From the foregoing description it will be seen that I contribute a lockmechanism which is exceedingly pick resistant in that successful pickingof the standard tumbler and drive assemblies will allow the plugs torotate a limited extent only so that entry will not be effected, itbeing remembered that successful picking requires a torque to be appliedto the plug being manipulated in order to maintain the picked tumblersin that condition. This same torque, necessary to maintain the standardassemblies picked, will also cause the limited rotation of the plugs. Onthe other hand, if it is attempted to pick the nonstandard assembliesfirst, the close fit of the standard assemblies in their respectivebores prevent sufiicient bearing being achieved to support anynonstandard drivers in picked condition; and even if this could beachieved in respect of one or two of them even the very faintestmovement or vibration will cause them to drop back into lockingcondition.

I also provide means associated with the lock mechanism whereby an alarmis given when unauthorized entry is attempted and without such entryhaving been achieved.

I believe that the construction and operation of my invention will nowbe understood and that the several advantages thereof will be fullyappreciated by those persons skilled in the art.

I claim:

1. Apparatus of the class described comprising: a cylinder, first andsecond plugs rotatably mounted in said cylinder in side by siderelation, means defining pairs of normally opposed bores in said plugs,a pin tumbler and driver assembly disposed in each of said pairs ofopposed bores normally to prevent establishment of an uninterruptedshear line between said plugs, a key slot in said first plug forreception of means adjusting said tumbler and driver assemblies toestablish an uninterrupted shear line between said plugs whereby saidfirst plug may be rotated independently of said second plug, at leastone of said pin tumbler and driver assemblies cooperating with saidplugs to transmit forces etfecting rotation of said first plug to saidsecond plug to effect counter-rotation thereof when said shear line isinterrupted by said force transmitting assembly and means limiting saidlast-mentioned rotation and counter-rotation.

2. Apparatus according to claim 1, wherein said cylinder and one of saidplugs are equipped with means tending to prevent relative movementtherebetween.

3. Apparatus according to claim 2, wherein said last mentioned meansincludes a spring loaded ball and groove detent.

4. Apparatus according to claim 1, wherein said second plug is providedwith switch operating means shiftable upon rotation of said second plugto effect actuation of a switch.

5. Apparatus according to claim 4, wherein said second plug and saidcylinder are equipped with detent means to retain said second plug inswitch actuating position.

6. Apparatus of the class described comprising: a cylinder, first andsecond plugs rotatably mounted in said cylinder in side by siderelation, means defining pairs of normally opposed bores in said plugs,a nonstandard pin tumbler and driver assembly disposed in each of saidpair of opposed bores normally to prevent establishment of anuninterrupted shear line between said plugs, a key slot in said firstplug for reception of means adjusting said tumbler and driver assembliesto establish an uninterrupted shear line between said plugs whereby saidfirst plug may be rotated independently of said second plug, at leastone of said pin tumbler and driver assemblies cooperating with saidplugs to transmit forces effecting rotation of said first plug to saidsecond plug to effect counter-rotation thereof when said shear line isinterrupted by said force transmitting assembly, means limiting saidlast-mentioned rotation and counter-rotation, and means definingnormally opposed bores in said cylinder and said first plug, a standardpin tumbler and driver assembly in each such pair of opposed boresnormally preventing establishment of an uninterrupted shear line betweensaid cylinder and first plug, said means adjusting said nonstandardassemblies also adjusting said standard assemblies to provide anuninterrupted shear line between said cylinder and first plug.

7. Apparatus according to claim 6, wherein said pin and driver assemblymeans are so constructed and arranged relatively to the bores that saidsecond plug is free to rotate a limited distance only in either annulardirection upon rotation of the first plug when the nonstandard assemblymeans are in normal position and said standard tumbler and driver meansare positioned to avoid interference with rotation of said first plug.

8. Apparatus according to claim 6, wherein said plugs each have aplurality of said bores and said nonstandard tumbler and driver assemblymeans comprise a tumbler, driver and spring means in each of saidopposed bores, the diameter of the bores in said second plug beinglarger than that of the bores in said key slotted plug.

9. Apparatus according to claim 6, wherein detent means are providedtending to retain said second plug in normal position.

10. Apparatus of the class described comprising: a cylinder, first andsecond plugs rotatably mounted in said cylinder in side by siderelation, means defining normally opposed bores in said plugs, a pintumbler and driver assembly disposed in each pair of said opposed boresnormally to prevent establishment of an uninterrupted shear line betweensaid plugs, a key slot in said first plug for reception of meansadjusting said tumbler and driver assemblies to establish anuninterrupted shear line between said plugs whereby said first plug maybe rotated independently of said second plug, bolt operating meansassociated with said first plug, said tumbler and driver assembliescooperating with said bores to permit limited rotation of said plugswhen said shear line is interrupted by at least one of said assemblies,said plugs being formed to interfere with one another when the extent ofsuch limited rotation is reached.

11. Apparatus according to claim 10, wherein said pin and tumblerassemblies comprise each a pin and a driver normally disposed in arespective bore of one of said plugs and a spring disposed in said boreand its opposed bore in the other of said plugs and urging the pin andtumbler to bottoming position whereby said spring normally intersectssaid shear line and afford a toggle action upon rotation of said secondplug.

12. Apparatus according to claim 10, wherein one of said plugs isrecessed and the other is formed with a projection extending into saidrecess, said recess and projection being constructed and arranged tointerfere at a preselected annular position of rotation thus to effect apositive limit of such rotation.

13. Apparatus according to claim 10, wherein means define normallyopposed bore means in said key slotted plug and said cylinder, a pin anddriver are disposed in said bore means and a spring urges same intonormal position wherein said driver intersects said shear line.

14. Apparatus according to claim 10, wherein switch operating means areassociated with said second plug and operate to actuate an alarm switchwhen said second plug is rotated such limited amount.

15. Apparatus according to claim 14, wherein detent means are providedto retain said second plug in switch actuating position, I 16 Apparatusof the class described comprising: a cylinder, first and second plugsrotatably mounted in said cylinder inside by side relation, meansdefining normally opposed bores in said plugs, a pin tumbler and driverassembly disposed in each pair of .said opposed bores, said assemblieseach including a pin tumbler and a driver, the latter normally seated onits respective pin tumbler in the respective bore in said first plug andextending into its respective bore in said second plug, saidbores insaid second plug being of a diameter larger than that of said drivers topermitlimited relatively counter-rotation of said plugs; a key slotinvsaid first plug for reception of means adjusting said-tumbleranddriver assemblies to establish an uninterrupted shear line betweensaidtplugs whereby said first plug may be rotated independently of saidsecondplug, and bolt operating means associated with saidfirst. plug. 7y

'17. Apparatus according to claim 16, wherein means define normallyopposed bore means in said cylinder and first plug, a-pinaand driver aredisposed in said bore means, and a spring urges same into normalposition wherein said driver extends into the bore means of both of saidplugs, said bore means in both plugs, afiording a close fit for saiddriver. i

v "18, Apparatus according to claim {16, wherein switch operating meansare associated with said second plug and operate to actuate an alarmswitch when saidsecon d plug is rotated such limited' amount. v

= 19. Apparatus according toclaim 1 8,'wherei n detent means normallyretain" said second plug in normal position and in switch operatingposition. y

References Cited p UNITE STATES PATENTS -'1,060;769 "5/1913 Kohlberger'70--364 1,088,648 Q2/1914 Birch 20042 2,870,622- --1/ l9 59 "Eriksson...l' 70364 3 3,319,443 5/1967 Perlick 70-421 MARVIN A. CHAMPION, PmaarExaminer R11 L. WOLFE, Assistant Examiner g 7 mom, 1 70478, 421, 422 e p

